Project Summary/Abstract The goal of this research is to advance the assessment of breast tumor margins using the new terahertz (THz) imaging technology. Following a lumpectomy surgery, excised tumor tissues are analyzed by pathologists to assess if the margins are positive where cancer cells extend to or very close to the edge of the tissue, negative where no cancer cells are found at more than one millimeter from the edge of excised tissue, or close margins which fall between positive and negative margins. Clinical studies reported that in 20-40% of cases excised breast tumor tissue contains positive margins necessitating a second operation. Phantom tissue (artificial materials) and mice model tumor will be used in this research as a preclinical study before THz imaging can be used in vivo and intra-operatively in the future. THz technology has recently emerged as a promising medical imaging modality. This technology offers several favorable features, such as high sub-millimeter resolution and sensitivity to water content, which is considered a major contrast factor in biological tissues. The investigators will focus the effort in this project on imaging two types of tumor tissues; the first type is developed phantom tissues that mimic freshly excised human tumors and the second type is freshly excised tumors grown in mice. The objective here is to establish a methodology of THz imaging of three dimensional tumors capable of assessing the tumor margins. The success of this research will help integrate this technology into the clinical application in the future. Dr. El-Shenawee, professor of electrical engineering and affiliated with biomedical engineering department, will lead the project at the University of Arkansas. She is collaborating with Dr. Rajaram, assistant professor of biomedical engineering, Dr. Wu, associate professor of electrical engineering, Dr. Chakraborty, assistant Professor of mathematical science (all at the University of Arkansas). She is also collaborating with Dr. Bailey DVM, PhD, DACVP, the Director of Oklahoma Animal Disease Diagnostic Laboratory (OADDL) at Oklahoma State University and with Dr. Campbell, MD, pathologist at Northwest Arkansas Pathology Associates in Fayetteville, AR. The involved investigators have expertise in THz imaging, signal and image processing techniques, statistical analysis, breast cancer in mice and clinical and animal pathology. The success of this research will lay the groundwork for fast, intraoperative tumor margin assessment and thereby significant reduction of second surgeries and cancer reoccurrence and metastasis